flake: use naersk to build cross arch docker images

3 files changed, 104 insertions, 23 deletions

diff --git a/parts/deployment.nix b/parts/deployment.nix
index 0aeea7b..1549c77 100644
--- a/parts/deployment.nix
+++ b/parts/deployment.nix
@@ -1,19 +1,94 @@
-{self, ...}: {
+{
+  inputs,
+  self,
+  ...
+}: {
+  flake.nixosModules.default = import ./module.nix self;
+
   perSystem = {
     lib,
     pkgs,
-    self',
+    system,
+    config,
+    inputs',
     ...
-  }: {
-    packages = {
-      container = pkgs.dockerTools.buildLayeredImage {
-        name = "teawiebot";
-        tag = "latest";
-        contents = [pkgs.dockerTools.caCertificates];
-        config.Cmd = [(lib.getExe self'.packages.teawiebot-smol)];
+  }: let
+    name = "getchoo/teawieBot";
+
+    crossPkgsFor = lib.fix (finalAttrs: {
+      "x86_64-linux" = {
+        "amd64" = pkgs.pkgsStatic;
+        "arm64v8" = pkgs.pkgsCross.aarch64-multiplatform.pkgsStatic;
+      };
+
+      "aarch64-linux" = {
+        "amd64" = pkgs.pkgsCross.musl64;
+        "arm64v8" = pkgs.pkgsStatic;
       };
+
+      "x86_64-darwin" = {
+        "amd64" = pkgs.pkgsCross.musl64;
+        "arm64v8" = pkgs.pkgsCross.aarch64-multiplatform.pkgsStatic;
+      };
+
+      "aarch64-darwin" = finalAttrs."x86_64-darwin";
+    });
+
+    nativeArchFor = {
+      "amd64" = "x86_64";
+      "arm64v8" = "aarch64";
     };
-  };
 
-  flake.nixosModules.default = import ./module.nix self;
+    wieFor = arch: let
+      target = "${nativeArchFor.${arch}}-unknown-linux-musl";
+      target' = builtins.replaceStrings ["-"] ["_"] target;
+      targetUpper = lib.toUpper target';
+
+      toolchain = with inputs'.fenix.packages;
+        combine [
+          minimal.cargo
+          minimal.rustc
+          targets.${target}.latest.rust-std
+        ];
+
+      naersk' = inputs.naersk.lib.${system}.override {
+        cargo = toolchain;
+        rustc = toolchain;
+      };
+
+      teawiebot = config.packages.teawiebot.override {
+        naersk = naersk';
+        optimizeSize = true;
+      };
+
+      inherit (crossPkgsFor.${system}.${arch}.stdenv) cc;
+    in
+      lib.getExe (
+        teawiebot.overrideAttrs (_:
+          lib.fix (finalAttrs: {
+            CARGO_BUILD_TARGET = target;
+            "CC_${target'}" = "${cc}/bin/${cc.targetPrefix}cc";
+            "CARGO_TARGET_${targetUpper}_RUSTFLAGS" = "-C target-feature=+crt-static";
+            "CARGO_TARGET_${targetUpper}_LINKER" = finalAttrs."CC_${target'}";
+          }))
+      );
+
+    toContainer = arch:
+      assert lib.assertMsg (
+        arch == "arch64" -> pkgs.stdenv.isLinux
+      ) "aarch64 images are only supported on linux!";
+        pkgs.dockerTools.buildLayeredImage {
+          inherit name;
+          tag = "latest-${arch}";
+          contents = [pkgs.dockerTools.caCertificates];
+          config.Cmd = [(wieFor arch)];
+
+          architecture = crossPkgsFor.${system}.${arch}.go.GOARCH;
+        };
+  in {
+    packages = {
+      container-amd64 = toContainer "amd64";
+      container-arm64v8 = toContainer "arm64v8";
+    };
+  };
 }
diff --git a/parts/derivation.nix b/parts/derivation.nix
index 8fc5bd8..57cf647 100644
--- a/parts/derivation.nix
+++ b/parts/derivation.nix
@@ -1,7 +1,7 @@
 {
   lib,
-  rustPlatform,
-  self,
+  naersk,
+  version,
   lto ? true,
   optimizeSize ? false,
 }: let
@@ -25,13 +25,11 @@
       inherit filter;
     };
 in
-  rustPlatform.buildRustPackage {
+  naersk.buildPackage {
     pname = "teawiebot";
-    version = builtins.substring 0 8 self.lastModifiedDate or "dirty";
+    inherit version;
 
-    src = filterSource self;
-
-    cargoLock.lockFile = ../Cargo.lock;
+    src = filterSource ../.;
 
     RUSTFLAGS =
       lib.optionalString lto " -C lto=thin -C embed-bitcode=yes"
diff --git a/parts/packages.nix b/parts/packages.nix
index 852db09..c4113c1 100644
--- a/parts/packages.nix
+++ b/parts/packages.nix
@@ -1,13 +1,21 @@
-{self, ...}: {
+{
+  self,
+  inputs,
+  ...
+}: {
   perSystem = {
     pkgs,
-    self',
+    system,
+    config,
     ...
   }: {
     packages = {
-      teawiebot = pkgs.callPackage ./derivation.nix {inherit self;};
-      teawiebot-smol = self'.packages.teawiebot.override {optimizeSize = true;};
-      default = self'.packages.teawiebot;
+      teawiebot = pkgs.callPackage ./derivation.nix {
+        version = builtins.substring 0 8 self.lastModifiedDate or "dirty";
+        naersk = inputs.naersk.lib.${system};
+      };
+
+      default = config.packages.teawiebot;
     };
   };
 }